Radio Receivers
If a FET is used as the first AF amplifier in a transistor receiver, this will have the effect of

Reducing the effect of noise at low modulation depths
Improving the effectiveness of the AGC
Reducing the effect of negative-peak clipping
Improving the selectivity of the receiver

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Radio Receivers
Indicate the false statement in connection with communications receivers.

Variable sensitivity is used to eliminate selective fading
Double conversion is used to improve image rejection
The noise limiter cuts off the receiver’s output during a noise pulse.
A product demodulator could be used for the reception of Morse code.

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Radio Receivers
In a radio receiver with simple AGC

An increase in signal strength produces more AGC
The highest AGC voltage is produced
The audio stage gain is normally controlled by the AGC
The faster the AGC time constant the more accurate the output

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Radio Receivers
Indicate the false statement. Noting that no carrier is transmitter with J3E, we see that

Adjacent-channel rejection is more difficult
Production of AGC is a rather complicated process
The transmission is not compatible with A3E
The receiver cannot use a phase comparator for AFC

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Radio Receivers
Show which of the following statements about the amplitude limiter is untrue:

The circuit is always biased in class C, by virtue of the leak-type bias.
Leak-type bias must be used
When the input increases past the threshold of the limiting, the gain decreases to keep the output constant.
The output must be tuned

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